Perhaps due to a commitment to lifelong learning, librarians are often willing participants in trying new technologies or service models that may benefit their patrons. Such an opportunity presents itself with massively open online courses, or MOOCs. This educational model, which has been gaining popularity in higher education since the first MOOC in 2008, is characterized by the premise of offering virtual educational opportunities to anyone who wants to participate. The result is a massive grouping of learners collaborating and producing content on a variety of platforms, including social media, learning management systems, and websites. While research on academic libraries' participation in MOOCs is still sparse, librarians have ample opportunities to participate in MOOCs both to become more familiar with the educational model and learn about the potential impact on public services. The reviews in this article feature sites for librarians to learn more about massively open online courses, as well as popular MOOCs and their individual courses that might be applicable to librarians.